Dana White has refused to draw comparisons between Chael Sonnen and the recently axed Nate Marquardt.

Marquardt is facing an uncertain future after being dropped by the UFC after he was found to have high levels of testosterone in his body ahead of his bout against Rick Story at UFC Live in Pittsburgh last weekend.

Both Marquardt and Sonnen claim to need Hormone Replacement Therapy, but while Sonnen has been backed by White, Marquardt has been told he will never fight in the UFC again.

Sonnen, who suffers from hypogonadism, admitted during a hearing in California his testosterone levels were high due to replacement therapy, but White believes Marquardt had one too many chances.

"The difference between Chael and Marquardt is we can talk about everything with the Chael incident," White said. "I've seen the stuff people are saying, like I'm this crazy, emotional psycho. Give me a break. This isn't the first time [for Marquardt]."

"To me, this is his fourth chance. He tested positive before [for anabolic steroids in 2006]. Then, he was apparently on suspension for New Jersey. Then he comes to [UFC Live in Pennsylvania] and doesn't pass his medicals. You tell me, is that his fourth chance?

"There's a difference between testosterone replacement therapy and getting to a level where it's performance enhancing," White said. "I'm the furthest thing from a doctor but, I guess, sometimes they need to get it back to a normal level.

"But if it's over that, you're taking too much or you're seeing the wrong doctor. It works for guys who absolutely need it but it's a messy loophole."

While White was adamant that Marquardt would not have another chance in the UFC, he did not rule out a possible return to MMA with Strikeforce.